1. Field of the Invention
The present invention generally relates to a light source module. More particularly, the present invention relates to a light source module and a micro projector using the same.
2. Description of Related Art
A projector is a display device for producing large-size images. An imaging principle of the projector is to convert an illuminating beam produced by a light source module to an image beam through a light valve, and projecting the image beam to a screen or a wall through a lens, to form an image. With the progress of the projecting technology and the reducing of the manufacturing cost, the use of the projector has been expanded from commercial use to domestic use.
A micro projector is similar to a conventional projector but has a smaller size and a lighter weight therefore can be integrated into a mobile device, such as a cell phone or a digital camera. The micro projection techniques currently adopted by micro projectors include a liquid crystal display (LCD) technique, a digital light processing (DLP) technique, a liquid crystal on silicon (LCoS) technique, and a micro electro mechanical systems (MEMS) micro scanner technique.
The light source of a projection apparatus may be a RGB light emitting diode (LED), or RGB laser diode (LD), etc. In existing micro projection systems, laser light sources in red, green, and blue colors are usually used as the light sources to provide rich colors. Taking the micro projectors adopting MEMS technique for example, a collimator lens is arranged in front of the laser light source and on a beam path of the light beam for collimating the light beam as a parallel light beam and the collimated light beam is reflected by the mirrors and filters so as to project the laser onto the micro mirror of the MEMS to project images with micro scanner technique. The RGB light sources alignment is thus critical for projecting quality of the micro-projection. Also, for better resolution of projection, the size of the light spot of RGB laser diode should be under 80 μm. Therefore, how to design a micro adjustment mechanism for precisely aligning the RGB light sources within limited space has become an important issue for people in the industry.